Borderless windowed mode is ideal in most cases I can think of. Window resizing must be disabled first, otherwise the mouse will be offset incorrectly. You can find this setting in game under:

Options > Display > Allow window resizing

Or in eqclient.ini:

AllowResize=0

Now the window borders can be properly removed by a third party utility such as this autohotkey script:

    ^!h::
    IfWinExist EverQuest
    {
       WinSet, Style, -0xC00000 ; hide title bar
       WinSet, Style, -0x40000 ; hide thickframe/sizebox
       WinMove, , , 0, 0, 1920, 1080
    }
    return

I like to tweak the default FPS settings to 60/60.

MaxFPS=60
MaxBGFPS=60

Gamma

Window gamma can be toggled off (it might even be off by default now)

WindowedGamma=0

Controls

Mouselook sensitivity can be adjusted under mouse options.

Definitely enable "Click Through Self" in General Options. Otherwise you'll have a hard time clicking anything remotely near your character. The target selection isn't quite so advanced.

TODO: Backup keyboard configuration

User Interface

Minimal UI available in this repo. I like to set the fade transparency level for most windows to 0%. The exceptions are the hotbars, spellbars and chat windows. I tweak the xml files to get those to behave minimally. The goal of a minimal interface is improved immersion. Use the UI options to load a window layout for your resolution as a good starting point. Copy UI_Player_server.ini into the game directory and you can try loading the window layout from it under General settings.

Text colors

Chat colors are stored as separate RGB values in eqclient.ini TextColors section. The default color scheme is a relatively dark palette. I've created an ir_black theme and included it seperately so you can just copy and replace it in eqclient.ini. This is an ideal light text on dark background scheme, so it'll only make sense if you have dark chat windows like I do. I have experimented with gradient backgrounds for chat windows, but the result wasn't great because I could only get 10 levels of transparency from a tga texture ingame.

Reorganize config files

There's over 4.3 thousand files sitting in the root game directory. If that irritates your OCD (or you hate having to look for the same file over and over again), you can reorganize a bit with symlinks. If you're not running the game from an SSD for some reason, I recommend doing this.